In over 55 years of using folding knives, mostly slip joints that do not have a blade lock of any kind, I have never had a blade close on me while using the knife to cut something. The same holds true when using a friction folder, like an Opinel, without using the twist lock.
Just because you "grew up" using a knife with a locking blade, and were never taught how to use a knife properly is not Buck's fault.
Now, before you get all huffy and show your ignorance by claiming "any knife without a locking blade is unsafe" (or words to that effect) consider this fact:
People have been using slip joints since the 1700's. They have been using friction folders even longer. (Note the above mentioned Opinel. While they have only been in production since roughly 1895, the twist lock, or ring lock, if you prefer, was not added until 1955, and even then, only on the size 6 and above. The size 5 and smaller do not have a blade lock. On the size 6 and above, use of the lock is optional. Many even take the lock ring off.)
When using a knife properly, the cutting action forces the blade open.
On a slip joint, the only purpose of the back spring is to keep the blade closed when not in use.
Most people do not have any need to stab cars or trucks. I know for a fact that in my 62 years on this rock, I have never had reason to ... And I doubt my great grandfathers did, either. (Both born circa 1890)
If you need to stab steel with a knife, you are using the wrong tool.
Buck has been making a good, durable, and affordable knife for over 100 years.
As stated by others, "just because it has a screw does not mean it is meant to be taken apart."
I would be wiling to bet you never even considered the possibility that Buck used something like red locktite to prevent the screws from coming out.
If you would bother to read the paperwork that came with your knife, you would see it specifically states not to take the knife apart.
By your own testimony, "the knife worked just fine for months" and "it only failed when you intentionally gave it a hard spine whack" which no doubt exerted far more stress to the lock than you would while using the knife the way it is designed to be used.
You talk of "the echo chamber" in the Spiderco forum.
Checkout the echo chamber in the Cold Steel forum. It is much, much worse than that of Spiderco.
If you are insane enough to mention a problem with a Cold Steel product in their forum, you will be driven out.
You might also want to consider the "intent to carry a weapon" laws in your location.
Cold Steel calls all of their products a "weapon" in their description. Just think what an anti-knife DA can (and will) do with that should you ever be facing a judge.
While you may claim "I was not carrying a weapon ..." The prosecuting "attorney" will counter "The manufacturer says it is a weapon and markets it as a weapon ..."